Water-arch for the furnaces of steam-boilers



R. G. SEAMAN.

WATER ARCH FOR THE FURNACES 0F STEAM BOILERS. APPLICATION FILED NOV-17, 1917.

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WATER ARCH FOR THE FURNACES 0F STEAM BOILERS.

MNllED STA'EES PAEFENT FIFEQE.

WATER-ARCH FOR THE FURNACES 0F STEAM-BOILERS.

Application filed November 17, 1917.

T 0 all whom it may concern:

Be it known that I, R BERT G. SEAMAN, a citizen of the United States, residing at Summerhill, in the county of Gambria and State of Pennsylvania, have invented new and useful Improvements in ater-Arches for the Furnaces of Steam-Boilers, of which the following is a specification.

This invention relates to water arches for -the furnaces of steam boilers, whether locomotive or stationary, and it has for its object to produce a water arch of simple and improved construction whereby the heating of the water supply to the boiler will be promoted and facilitated.

A further object of the invention is to produce a simple and improved construction whereby the gases of combustion will be mixed, and the ends of the boiler fiues protected from sudden and uneven expansion or contraction caused by improperly mixed gases of different degrees of temperature.

A further object of the invention is to provide a fire brick protection for the arch but which will serve not merely as a protection for the arch but which will also by the absorption and radiation of heat contribute materially to the maintenance of an even and high temperature whereby useful results are promoted.

Further objects of the invention are to simplify and improve the construction and arrangement of the, detailed parts entering into the construction of the improved devlce.

With these and other ends in View which will readily appear as the nature of the invention is better understood, the same consists in the improved construction, novel arrangement and combination of parts which will be hereinafter fully described and particularly pointed out in the claims.

In the accompanying drawings has been illustrated a simple and preferred form of the invention, it being, however, understood that no limitation is necessarily made to the precise structural details thereinexhibited, but that changes, alterations and modifications within the scope of the claims maybe resorted to when desired.

In the drawings Figure 1 is a longitudinal sectional view of a boiler and furnace constructed in accordance with the invention, the section being on line 1-l of Fig. 8.

Specification of Letters Patent.

Patented Nov. 15, 1921. Serial No. 202,547.

Fig. 2 is a sectional detail view, enlarged, of the arch.

Fig. 3 is a top plan view showing sections of the arch detached, the brickwork being omitted.

Fig. 4 is a detail view of a portion ofthe arch taken on the line 4-4 in Fig. 3.

Fig. 5 is a vertical cross section taken on the line 55 in Fig. 1.

Fig. 6 is a vertical cross section taken on the line 6-6 in Fig. 1.

F 7 is a bottom view of the arch.

Fig. 8 is a horizontal sectional view taken on the line 88 in Fig. 1.

Fig. 9 is a sectional detail view illustrating a modification.

Corresponding parts in the several figures are denoted by like characters of reference.

Referring to the drawings, A designates the furnace and B the boiler. A is the fire chamber. O is the fire door opening, D the grate bar level, E,'the gas chamber, F, the boiler fines, G, the smoke box, and H, the chimney or exit for the products of combustion.

Arranged within the furnace box and depending from the boiler casing 15 are hanger plates 16 forming water compartments or water legs 17 that communicate; with the water space of the arch as will be presently described. The hanger plates are connected together in pairs by numerous stay bolts 18, a large number of suchstay bolts being used throughout the construction of the device in order to enable the parts to resist any strain to which they may be subjected by the pressure of the steam when the device is in operation. The hanger plates serve to support numerous transversely arranged short pipes or fiues 19 for the passage of products of combustion.

Arranged in the inter-spaces between the water legs 17 and also in the interspaces between said water legs and the water legs 20 which constitute the side walls of the furnace, are the top casing members 21 of the arch K which in addition to said top casing members comprises the bottom casing sheet 22, said top and bottom sheets being connected together by stay bolts 22. Sheet 22 is provided with extensions 25, illustrated in Fig. 7, these elements extending under the rear portions of the water legs, and the openings between said elements permitting gases to pass from the lower forward portion of the firebox rearwardly and upwardly, thence over the arch to the boiler flues. Extending lengthwise between the top and bottom sheets 21-22'are tubes or ducts 23 the in takes of which connect with the bottom sheet 22 near the front end of the latter and the outlets of which communicate with the top sheets 21 near the front ends thereof. The arch is supported in an inclined position as shown, being inclined downwardly and forwardly with respect to the furnace box. The arch K communicates at its lower forward end with the bottom space of the boiler, and the side walls 27 which connect the top sheets 21 with the bottom sheet 22 of the arch are provided with openings 28 through which the water arch is in communication with the respective water legs 17 and 20 as will be readily apparent by reference to the drawings. The topwall of each of the arches is covered with and protected by a layer of fire brick 28. The lower sheet of the water legs, where the latter depend into the arch, is shown at 24, and 25 indicates that portion 0 this sheet beyond the arch.

In operation the gases of combustion from the forward end of'the fire chamber will be forced to circulate through ducts or fiues 23 reaching the gas chamber E which consists not merely of the space between the water legs 17 and the flue sheet 30 of the boiler, but which extends in the spaces between the forward ends of the water legs 17 and 20 as best seen in Fig. 8. The gases of combustion from the rear or back portion of the fire chamber will be forced to circulate in .the rearward portions of the spaces between the water legs 17 and 20, which spaces may be regarded as constituting a portion of the fire box, into the gas chamber E, and there mixing with the gases coming through the ducts or flues 23, passing thence through the boiler flue to the smoke box G and the exit H.

The gases of combustion in the gas chamber E will be induced to circulate and to radiate heat from one part of the gas chamber E to another through the transverse ducts or flues19 of the water legs 17. The water legs 17 being directly connected with the boiler casing 15 and with the water arch will promote circulation between the contents of the boiler proper and the contents of the arch K. The contents of the water legs 17 as well as the contents of the water arch K will be subjected to very effective heating by absorption through the casing members 16, 21 and 22 as well as the walls of the ducts or flues 28 and the walls of they transverse ducts or flues 19, thereby materially increasing the heating surface and the steam making capacity of the boiler; The gases of combustion in passing to the fiues or boiler tubes are forced to pass over the heated brick whereby the top walls of the arches are covered and protected, and any gases of a lower degree of temperature than the brick will be heated or the temperature thereof will be raised, thereby mixing the gases and promoting combustion aswell as protecting the fiues or boiler tubes from sudden and uneven contraction and expansion caused by the contact therewith of gases of different and uneven temperature. The brick retains the heat for a considerable interval, and effects the result stated when thefire has partly died down over. a given portion of the grate. It may also be stated that in engine furnace pro-- vided with superheating mechamsm or with boilers having superheating tube units and under other similar conditions, when the engine is shut off,'drifting or not working under a full head of steam it is customary to utilize a damper of well known construction for the purpose of shutting off the gases of combustion from the superheating tube units, thereby inducing and forcing the gases of combustion to pass into the lower boiler tubes and fines, thus causing the gases of combustion to pass in closer relation to and above the fire brick whereby the heat will be absorbed and conserved. This will also tend to protect the boiler tubes and flue sheet from sudden contraction or expansion.

In Fig. 9 of the drawings a modified form have in Fig. 9 shown a modification which consists in using flues, here designated by 19, of substantially inverted V-shape presenting inclined end portions that incline downwardl from the central or intermediate portions. shes and other obstructions will readily slide from the inclined portions of the fines instead of settling thereon, this being especially thecase in the application of the invention to locomotive boilers where the vibration of the enginewill assist materially in causing the obstructions to slide from the inclined portions ofthe flues back into the fire box. 7

Having thus described the invention, what isclaimed as new is:

1. In a boiler furnace having upper and lower portions, an inclined water arch comprising a casing having top and bottom walls and longitudinal flues extending through the casing, said flues having intakes opening through the bottom wall near the.

lower forward end of the firebox, and having outlets through the top Wall of the casing, discharging at a point approximately midway of the front and rear walls of the furnace, the upper and lower portions of the furnace chamber being in communication at the rear of the water arch.

2. In a boiler furnace and having upper and lower portions, including a crown sheet and front and rear walls, a water arch including longitudinalfiues opening through the lower wall of the arch near the forward end of the firebox, and opening through the upper wall approximately midway of the front and rear walls of the furnace, the upper and power portions of the furnace chamber being in communication at the rear of the water arch, and water legs extending perpendicularly with reference to the arch, depending into the body thereof, and dividing the upper portion of the furnace chamber longitudinally, said water legs depend ing from the crown sheet, acting as stays for the arch and extending to the rear wall.

3. In a boiler furnace, a plurality of hanger plates forming water legs and additional water legs formed by the side walls of the furnace, a water arch into which the first-mentioned water legs extend, said arch being in communication with the several water legs, and longitudinal fiues extending through the water arch for the passage of products of combustion; some of the water legs being provided with transverse flues arranged for the passage of products of combustion, and flues having intakes communicating with the bottom plate of the arch near the forward end of the latter and outlets communicating with the top members of the arch near the rearward ends thereof and discharging into the interspaces between the water legs.

In testimony whereof I afiix my si nature.

ROBERT G. SEA IAN. 

